Ln3+ 4f Energy Levels in CaTiO3 Analyzed by XPS Measurements
Ln3+ 4f Energy Levels in CaTiO3 Analyzed by XPS Measurements
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DOI：
10.1002/pssa.201700776
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
R. Yamamoto;Kazushige Ueda
中科院分区：
文献类型：
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作者：
R. Yamamoto;Kazushige Ueda
用X射线光电子能谱（XPS）分析了CaTiO3中Ln3+ 4f基态的能级。XPS光谱中的ln4f态是利用ln4f和o2p态之间的大光解离截面差提取出来的。在价带最大值处，Pr3+的Ln3+ 4f能级为0.8 eV， Gd3+为−5.0 eV， Tb3+为0.9 eV， Lu3+为−4.6 eV。虽然所得的Gd3+和Lu3+ 4f的价带值较深，但Pr3+和Tb3+ 4f的价带值与先前报道的值吻合较好。Pr3+掺杂的CaTiO3和CaZrO3在光致发光颜色上的差异可以简单地从位于带隙中的Pr3+ 4f能级来解释。
The energy levels of Ln3+ 4f ground states in CaTiO3 are analyzed using X‐ray photoelectron spectroscopy (XPS). The Ln 4f states in the XPS spectra are extracted utilizing large photoionization cross section differences between Ln 4f and O 2p states. The Ln3+ 4f energy levels referred to the valence band maximum are evaluated to be 0.8 eV for Pr3+, −5.0 eV for Gd3+, 0.9 eV for Tb3+, and −4.6 eV for Lu3+ from the extracted XPS spectra. Although the obtained values of Gd3+ and Lu3+ 4f levels are deeper in the valence band, the values of Pr3+ and Tb3+ 4f levels are in good agreement with those reported previously. The difference in the photoluminescence colors between Pr3+‐doped CaTiO3 and CaZrO3 is simply explained from the Pr3+ 4f energy levels located in the bandgaps.